Somatic Embryogenesis in Stationary Phase Suspension Cultures Derived from Hypocotyl Protoplasts of Brassica Napus L.

Abstract

To get more efficient regeneration of plants from hypocotyl protoplast-derived suspension cultures of Brassica napus, investigations regarding the time course of cultivation for the formation of somatic embryos were carried out. Although regeneration of plants from hypocotyl protoplasts via callus is sometimes efficient (Glimelius 1984, Chuong et al. 1985, 1987, Barsby et al. 1986), shoot morphogenesis is often not reproducible, when other genotypes are used in regeneration experiments. Reproducible plant regeneration procedures from protoplasts of Brassica species are still needed (Chuong et al. 1987). Most useful may be the regeneration of plants via somatic embryogenesis. Li and Kohlenbach (1982) obtained somatic embryogenesis from protoplast-derived cultures by testing various media, especially the hormone compositions. Our data demonstrate the importance of the choice of stationary phase aggregates as inoculum for embryoid formation in hypocotyl derived suspension cultures of Brassica napus L. These findings may be of general importance, since embryoid formation, greening and plant regeneration could be achieved with an embryogenic line of Digitalis lanata, using a similar sequence of passages. Stationary and late stationary phase cells showed the highest degree of embryoid formation followed by greening and plantlet formation.